Disk drives using various kinds of recording disks, such as optical disks, magneto-optical disks, and flexible magnetic-recording disks, are known in the art. In particular, hard-disk drives (HDDs) are widely used as indispensable data-storage devices for contemporary computer systems. Moreover, HDDs have found widespread application to motion picture recording and reproducing apparatuses, car navigation systems, cellular phones, and similar devices in addition to computers, due to their outstanding data-storage characteristics.
A magnetic-recording disk used in a HDD includes multiple concentric data tracks and servo tracks. Each data track includes a plurality of data sectors containing user data recorded thereon. Each servo track contains address information. A servo track includes a plurality of servo data regions arranged discretely in the circumferential direction, and one or more data sectors are recorded between servo data regions. A magnetic-recording head is configured to access a designated data sector in accordance with address information in the servo data to write data to, and read data from, the data sector.
The magnetic-recording head is formed on a slider; the slider is bonded to a suspension of an actuator. The assembly of the actuator and the head-slider is called a head-stack assembly (HSA), and the assembly of the suspension and the head-slider is called a head-gimbal assembly (HGA). Pressure produced by air viscosity between an air bearing surface (ABS) of the slider facing a magnetic-recording disk and a spinning magnetic-recording disk balances a force applied by the suspension toward the magnetic-recording disk, so that the head-slider flies in proximity to the recording surface of the magnetic-recording disk at a specific fly height. The actuator rotates on a pivot shaft to move the head-slider to a target track and position the head-slider on the track.
As the number of tracks per inch (TPI) on the magnetic-recording disk, which is one measure of data-storage capacity, increases, the positioning accuracy of the head-slider has correspondingly increased. However, there is a limit to the positioning accuracy of an actuator that is driven with a voice coil motor (VCM). Therefore, an approach is known in the art that mounts a compact actuator, which is referred to by the term of art, “microactuator,” on a distal end of the actuator to achieve finer positioning. Therefore, engineers and scientists engaged in HDD manufacturing and development are interested in the design of HGAs, microactuators and methods of manufacturing the microactuator to meet the rising demands of the marketplace for increased data-storage capacity, performance, and reliability.